Hi ycarry,

> With last ios version 11.3, this forum is no more usable on iPad... /:^(
> no scrolling, pages truncated at screen size...

Wow that's unfortunate they have such a break in compatibility.

You might try the mobile version without frames which you can use here:
http://moi3d.com/forum/index.php?webtag=MOI&noframes


> maybe time to upgrade ?

It's hard to say if the latest version of Beehive is any different, can you try here and see if that works ok or not :
https://tehforum.co.uk/forum/

- Michael